SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4311caa27bb6e688f1652f493638061e60157af051598a045352477cd97c0e2' 
  AND token = 'kgq61wxjoIOtWDFWFu7CVylOP0RFqiyqKd2r8YFeafA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}